A couple of teams have emailed me about orbit validation, so this thread is for teams to bounce ideas around. The rules state that acceptable proof-of-orbit criteria must be agreed with the organizers before launch, and there are several possible ways of acheiving this. So, feel free to ask questions or suggest methods...

For orbit validation I've assumed the obvious--RF transmission. As mentioned in my SAS presentation ( http://www.microlaunchers.com/7816/L3/sa09/sa09.html ) a small transmitter using cell phone components is suggested, with a battery to support perhaps 2 days (9 orbits = 14 hours), and allow verification via unrestricted access, reporting of reception.

A problem for US is the licensing, and that is being investigated. Use of an amateur license (I'm KD6HKU) would be illegal for a prize attempt, but could be ok for a test flight that's understood to not be an entry.

A strobe or some optical method would not require a license, but the physics suggests it would be difficult. I will do some calculations, see if it's even worth continuing with.

In any case I assume some unambiguous indepentently verifiable proof is needed.

Will yourself "N-Prize" look at validating the orbits yourself by some outside means? If this is possible?Or the data of the orbits by the team launching be made public to other teams, in case of inacuricies, maybe the leaders of other teams there on the day to also confirm. Just a thought.

I think validation would be easy if the means is RF transmission. The signal format, frequency would be published, and it's certain many hams the world over would catch the signal and report it. I remember Sputnik-1 That's just what happened. An N Prize entrant only needs to last clearly over about 14 hours (9 orbits) and free verification is assured.

I'm going to do some calculations about whether a xenon strobe, diode laser, or flashing LED is at all feasible. This would rely on amateur astronomers being able to spot, report it. An optical signal would not require a license.

Iain - to answer your question about whether I will be validating orbits directly, that's unlikely, as it's liable to need appropriate radio equipment, optical telescopes or whatever is dictated by the orbital validation method chosen by the entrant. The exact method needs to be agreed between me and the entrant before launch, but Charles is right in saying that radio is probably the most straightforward.

For example, if it's a radio signal that can be detected by a wide range of people, then the entrant and myself need to agree on a reasonable number of parties who will monitor the signal and confirm the orbits, and who have no direct interest in the result. The same would go for optical tracking, etc. I can guarantee that I won't be unreasonable in the level of proof required, but it will have to be rigorous.

I think Pete Jones (Nebula) has also looked closely into the options for optical detection, both active (flashing) or passive (big white balloon!).

By the way, guys, can I direct your attention to the post under "PR"? I'm still trying to get some preliminary material together to send to "Wired"....